On the negative dipole moment derivatives of HNgX molecules

The HNgX (Ng = Ar, Kr; X = F, Cl) molecules were studied using the CCFDF model about a decade ago[1] because the stretching of this bond leads to a decrease of the molecular dipole moment, while for most molecules the opposite is observed. After that, substantial improvements were achieved to this partition scheme until a new model was proposed, called CCTDP[2]. Although the latter can be viewed as a rearrangement of the CCFDF terms, it provides us deeper and more accurate interpretations of IR intensities. In this work the CCTDP model will be used to analyze the dipole moment derivatives of HNgX (Ng = Ar, Kr; X = F, Cl, Br) and compare them with the derivatives for the respective HX molecules.